Compounded oil



COMPO l Bruce B. Farrington, Victor M. Kostainsek, and

George H. Denison, Jr., Berkeley, calm, assignors to Standard Oil Company of California,- San Francisco,- Calif a corporation of Delawere No Drawing. Application Feb" Serial No. 331,11!

18 Claims. (Cl. 252-32) temperatures and thelike, caused by relativelyv recent changes in engine design. The prevention of undue corrosion by lubricants encountering these conditions is increasingly diflicult for three principal reasons.

The first reason is that the newer bearing metals are, in general, more susceptible to the destructive agents of a corrosive nature even though these metals are harder and capable of carrying higher loads than were the conventional Babbitt bearings. Typical of these corrosionsusceptible newer bearings are those composed of cadmium-silver or copper-lead alloys supported upon a steel back. Others of these relatively new bearing metals are cadmium-nickel alloys and the so-called high lead bearings.

The second reason for increasing difilculty in preventing corrosion is that the changes in engine design have required concurrent marked advances in methods of refining lubricating oils to yield products having high viscosity index or other desired, properties. This demand for oils having lesser change in viscosity with changes in temperature, 1. e. higher viscosity index, has been met by refining lubricants by certainselective solvent refining or selective solvent extraction processes wherein the lower viscosity index hydrocarbons are selectively dissolved. The selective solvent refining processes are operated to concentrate in one fraction, usually the undissolved lubricant fract on, those compounds of a "para-mnic nature which show a smaller change in viscosity upon change in temperature. Selective solvent extraction processes have been found in many cases to yield an oil which, although satisfactory from the standpoint of viscosity index, is over-refined as respects stability at higher temperatures. This is particularly true where the selective solvent refinement is carried to a point which yields high viscosity index products.

By "over-refined oils it is intended to designate those oils from which naturally-occurring inhibitors normally present in the oil have been removed at least to an extent which materially necessarily high viscosity index oils since oils of intermediate viscosity index are sometimes produced from quite low viscosity index stocks by a severe refinement which causes a substantial reduction in the natural inhibitorcontent of the oil and thereby produces an oil having a correspondingly reduced stability. From the above it should be apparent that over-refined oils are not limited to those produced by solvent extraction. Other refining processes, e. g. sulfuric acid treatment to produce white oils, remove naturallyoccurring inhibitors originally in the oil when the treatment is sumciently severe and thereby produce over-refinement with the attendant difliculties herein discussed.

In general, over-refined oils may be characterized as having natural inhibitors removed to the point where the corrosiveness of the oil is greater than about 40 mgs. on a 1" x 2" coarse-grained copper-lead bearing in a 12-hour corrosion test (subsequently described in more detail) run under the following conditions:

Air rate 300' F.

Temperature 30 liters per hour Catalyst 10 gms. oi steel wool and a 6" x 1" copper strip The foregoing 40 mgs. loss in the 72-hour corrosion test may be designated as a corrosion index of 40.

The solvent refined oils referred to above, and especially the over-refined oils, are not the only type of oils which become definitely corrosive to the newer bearing metals under normal but severe conditions of use in internal combustion engines. It has been found that a corresponding adverse reaction, namely, corrosion of alloy hearing metals such as cadmium-silver alloys. also occurs in paraflinic base oils which have not been solvent refined or over-refined. These corrosion difliculties sometimes cause bearing failure after only a few thousand miles of operation; The higher the viscosity index of the lubricating oil the more pronounced, in general, is the tendency to corrosion of the kind referred to above. Generally speaking, theproblem is encountered in oils having viscosity indexes oi 75 and higher, and becomes of major magnitude in oi s having a viscosity index of toy to or higher.

Thirdly, the newer engines require that the crankcase lubricants operate under significantly higher temperatures than heretofore required. It is found that lubricating oils, which are satisfactory and non-corrosive on newer alloy bearings at lower temperatures heretofore normally encountered, become unduly corrosive to these same bearings at the higher temperatures. These higher temperatures approach the borderline of stability of organic compounds and relatively 'small increases in temperature therefore magnify many-fold the difficulties of inhibiting corrosion and other deterioration, such as formation of varnish, carbon, orsludge. v

, Problems in lubrication of internal combustion engines have been further multiplied by the necessity for addition of stabilizers capable of,

agents such as aryl metal oxides (metalphenates), salts of aryl carboxylic acids, salts of polycarboxylic acids which preferably have'been partially esterified, salts of alkyl carboxylic acids containing a polar group (e. g. mercapto, thioketo, ,thioether, amino, cyano, phosphino, oxyketo, and hydroxy groups, and thelike) near a carboxyl group of the acid, and metal alcoholates.

ascent? A feature or this invention comprises the pro-.

' vision of a lubricating oil containing a new com-- As engine condi- These types of stabilizers are relatively non-cor- In naphthenic base lubricating-oils, or even in i oils of intermediate refinement and intermediate viscosity index (a g., a viscosity index of less than 75) which are not over-refined, various corrosion inhibitors are highly effective under severe service. However, when an over-refined or high viscosity index oil (e. g. of 80 viscosity index or more) is used as a base stock and when the oil is to do service under extreme conditions on corrosion-sensitive alloy bearings, the difilculties presented have seemed almost insurmountable. Thus there was presented a combination of circumstances not previously encountered, namely: (a) the necessity for lubricating corrosion-sensitive hard alloy bearings, (17) the desirability, of using a base oil stock inherently more corrosive to such bearings than lower viscosity index or less highly refined oils, and. (c) more severe operating conditions, as respects temperature and speed, than the lubricating engineer had previously been requested to meet.

Under this new combination of circumstances it was found that the above-mentioned non-corrosive stabilizers against deterioration at elevated temperatures catalyzed corrosion by the oil although these compounds remained non-corrosive in themselves. Also, it was discovered that various corrosion inhibitors found to be eil'ective to prevent corrosion even by the over-refined or higher viscosity index stocks in the absence of the stabilizers were not effective as anti-catalysts to destroy the catalytic corrosion of the stabilizers in such oils. In others words, the anti-catalytic action of an inhibitor in uncompounded hydrocarbon oils formed no adequate basis for predicting that the same inhibitor would selectively "poison the stabilizing agent oicompounded oils and destroy the agent's catalysis of corrosion without also destroying its catalytic stabilizing agglon against deterioration at elevated tempera es.

bination of additives. This new combination of additives is highly effective, both as respects stabilization against deposition of adhesive or resin ous materials at elevated temperatures and prevention of corrosion of alloy bearings, when incorporated in over-refined lubricating oils and oils having a viscosity' index higher than 75, e. g.

a viscosity index of to or higher. Since the new combination of additives iseifective even in hydrocarbon lubricating oils which are relatively non-responsive to corrosion inhibitors and stabilizers, the combinations disclosed in'more detail hereinafter'are exceedingly powerful additives for more responsive oils, such as naphthenic or mixed base lubricants containing'naturallyoccurring inhibitors in normal quantities or in oils having a viscosity index of less than 86.

The corrosion inhibitors of this invention cornprise long carbon chain multi-bridg ed thioalkyl compounds, and the preferred type is termed herein "alkyi polythio dimero."

These inhibitors are exemplified by compounds of the following type formulae:

and preferably at least R; or R4 is also a long carbon chain. All four of these radicals, R1, Ra, R:

75 and R4, need not be long chains; for example, R2

and Re may be short chains or even hydrogen when R1 and Rs are long chains. Compounds in which only one or the radicals, e. 3- Bi. is a long carbon chain are not precludedl Likewise, these radicals may contain cyclic substituents such as an aromatic or naphthenic substituent. Howchain. However, modifications at present less preferred but -within the scope of the invention in its broader aspects include multi-bridged thio compounds in which the terminal valences of the ever, such carbocyclic substituents, if present,

should be positioned in a long chain on a carbon atom relatively distant from the bridged sulfur group or groups since it is desired that the sulfur groups possess substantially the properties oi bridged thioalkyl substituents.

The term "dimer" as used herein designates a type of product such as produced by linking together two molecules of hydrocarbonstructure by a condensation reaction. Such a reaction is' -free valence of each molecule to thereby connect the molecule together, thus:

The carbon chains so condensed need not be identical or of the same number of carbon atoms to fall within the meaning of the term dimer" as used herein. Similarly, the term "trimer is used to designate compounds in which three molecules are connected by such a condensation reaction.

The term alkyl polythio-dimer designates a condensation product of two molecules of hydrocarbon structure in which at least two sulfur atoms independently bridge and connect alkyl carbon chains. Such a dimer is produced by a condensation of two polyhalogenated alkyl molecules in which at least two halogen atoms are split out from each alkyl molecule and at least two sulfur atoms form connecting links between the free valences of the two molecules. A significant distinguishing characteristic of these compounds is that at least two carbon atoms of a chain separate the terminal valences of the bridging sulfur atoms, thus:

A i JJ-L l l Poly-(monothiomimer l l Poly-(ditiiio)dimar ferred type of compounds insofar as it is indi- \be prepared by various methods.

sulfur bridges are separated by more than two intervening carbons of the chain. As previously indicated, at least one long carbon chain should be present in the compounds. By "long carbon chain" it is intended todesignate a carbon chain having eight to ten or more carbon atoms, and preferably twenty or more carbon atoms. Relatively straight chain; are preferred, although branching in the chain is not precluded; for example, 'butene and isobutene polymers yield long carbon chains having some branches but are suitable for the purposes of this invention. Paraflln wax is an illustration of a composition containing long carbon chains of outstanding yaiue for synthesis of the corrosion inhibitors herein disclosed.

The corrosion inhibiting thiomers or this invention may contain organic or inorganic substituents in one or more of the carbon chains. Examples of such substituents are the halogens (chlorine, bromine and iodine), ester groups, hydroxyl groups, and metal carboxylate roups.

The corrosion inhibitors of this invention may The following are equations for exemplary reactions:

(l) Reaction of halogenated long chain hydrocarbons and an inorganic sulfide in the (2) Preparation of a mercaptide and reaction with a halogenated hydrocarbon, one or both being long chain compounds:

tide with various oxidizing agents:

Additional types of compounds illustrating the invention in its broader aspects are:

Tri- (bridged monothio) dimers- K H H R-Ji--il-H i i i n--tnt-m it it Tri- (bridged disulflde) dimerscarbon atoms long and yield oil-soluble products.

higher polymers are useful. Thus the trimers and tetramers are contemplatedn- Z-E-n nc -i-m R-E-Z-H HZE-EERs i l i i i t n i t t t n. Heals.

where R, R1, R2 and Rs are radicals of hydrocarbon structure.

However, it is preferred that the compound or mixture of compounds should be liquid at ordinary atmospheric temperature. For this reason. dimers, trimers or mixtures of dimers and trimers are at present utilized.

It has been discovered that a reaction product comprising an unknown mixture of thiomers is an outstanding corrosion inhibitor. This reaction product contains a mixture of different sulfides which cooperate in some unknown manner to produce a powerful corrosive inhibiting action effective at hi h temperatures and in high viscosity index oils. The reaction product is believed to be a mixture of multi-bridged thiomers, monothio others, dithio ethers and probably a small proportion of trithio ethers. This particular reaction product is one of applicants preferred species. The reaction product is herein designated paraffin wax thiomers and comprises the product of the reaction of a halogenated parafiln wax (preferably containing from about 15 to about chlorine) and an inorganic sulfide such as sodium sulfide or polysulfide.

In order to illustrate the invention and facilitate the practice thereof by those skilled in the art. the following examples of methods of preparing wax thiomers are given:

PREPARATION OF CHLORINATED WAX Crude white scale wax is melted and heated to about to 200 F. and chlorine gas is passed throughthe melt. The temperature is preferably kept between these limits by adjusting the rates of heating and inflow of chlorine. The density of the mix increases rapidly as the chlorination proceeds and the gravity of the reaction product is thus a measure of the degree of chlorination. When the chlorine content of the wax has reached a desirable percentage the flow of chlorine gas is cut off and the mixture is blown with either nitrogen or air until substantially free of either chlorine gas or hydrogen chloride. The chlorinated wax is a straw-coloredliquid which slowly darkens on standing. Exemplary inspections of such chlorinated waxes are as follows:

Per cent Gravi 01 PREPARATION OF WAX THIOMEBS EXAMPLE].

The proportions of the reactants are given in the table below:

Beactants Grams Gram mole:

Chlorinated wax (27.5% chlorine) 8, 520 19 Sodium sulfide (60-62% mus)... 8. 760 29. 5 Sulfu sec 21. 7 Alcohol 1 19,001 414 star a, 186 11s The sodium sulfide utilized was approximately a trihydrate and the amount of water added was just suflicient to produce NaaS.9HaO.

In preparing the wax thiomers the chlorinated wax and alcohol are first thoroughly mixed in a vessel equipped with a stirrer and a reflux condenser. The sodium sulfide is dissolved in the heated water. The sulfur is added and the mixture boiled and stirred until the sulfur dissolves in the aqueous solution. This aqueous solution is added to the alcoholic solution of the chlorinated waxand the whole is refluxed at F. (atmospheric pressure) for twenty hours. The reaction product is then washed with water until free of alcohol and inorganic salts and then dried by air-blowing it at elevated temperature. After drying, the final product is filtered.

In a preferred embodiment of the invention the reaction is carried out under conditions such that substantially all the chlorine in the chlorinated wax is removed. In order to facilitate production of this type of prduct it is preferred that the chlorinated wax contain only about 16% chlorine.

The following table gives analytical results on the various batches of parafdn wax thiomers pre- 1 Method 1--B0fl1 alcohol and water are used as in the description given above. Method 2-0111! alcohol is used as a solvent, and the sodium sulfide and sulfur are added directly to the chlorinated wax in alcohol. Method 3- Half the quantity of alcohol and water are used.

Exsm'u: 2

To insure a wax thiomer substantially free of chlorine the following process was utilized:

Chlorinated wax in this example contained 16% chlorine and anhydrous sodium sulfide was used. No water was added and the alcohol was anhydrous. The proportions were as follows:

Beactantl Grams Gram moles in 16 chlorine 800 1.9 Chlor atedtglvax 1m 4. 35

The sodium was dissolved in 800 grams of alcohol and half of the resulting sodium ethylate solution saturated with hydrogen sulfide to yield anhydrous sodium hydrosulfide. To this solution the other half of the sodium ethylate was added.

The chlorinated wax was dissolved in 800 grams of alcohol and heated to 160 F. The alcoholic reaction product of sodium ethylate and sodium hydrogen slufide (anhydrous sodium sulfide) was added and the sulfur stirred in. The whole mixture was refluxed for nineteen hours, washed, dissolved in ethyl ether and dried with anhydrous sodium sulfate. After filtering, the ether was evaporated oif.

Yield g ams 701 Viscosity at 100 F 1224 Per cent S 12.6

Per cent 1.8

Exlmrn: 3

- According to this method wax multi-bridged monothio dimers may be prepared as follows:

Chlorinated wax (15 to 25% chlorine) was reacted with an alcoholic solution of sodium hydrosulfide to yield wax mercaptan by the reaction-- s11 ClwaxCl+2NaSH(alcoholic) ---o wax +2NaCl The wax mercaptan is then converted to alkaline metal mercaptides by reaction with caustic soda or sodium ethylate as follows:

SH 4 SM; Wax +2NaOH Wax +2mo sn em The wax mercaptide is then reacted with additional chlorinated wax (15 to 25% chlorine) in a wax multi-bridsed A typical product of this method had a molecular weight of.873, a sulfur content of 6.8%, and a chlorine content of 2.2%.

Exmu-i A wax multi-bridged disulfide may be prepared from the wax mercaptans of Example 3 by oxidation of the mercaptans as follows:

4 L in.

2Wax

- oxidizing agents other than oxygen may be utilized; for example, iodine, alkali hypochlorites or hyp chlorous acid.

Exams: 5

Dissolve grams of wax polymercaptan (16.4% S, 2.5% CI, molecular weight 370, viscosity at 100 F.=210.1) in 400 cc. of petroleum ether. Slowly stir in 496 grams of a 5.25% by weight NaClO aqueous solution and thoroughly agitate for about one hour. Separate the aqueous layer, wash the petroleum ether solution with water, dry, filter and evaporate off the petroleum ether to leave a wax multi-bridged disulfide containing 16.4% sulfur.

Exams: 8

A wax multi-bridged disulfide containing 12.9% sulfur and 1.8% chlorine was prepared by the method of Example 5 utilizing 100 grams of wax polymercaptan (12.3% sulfur, 1.9% chlorine, molecular weight 530, viscosity at 100 F=153.5) and 410 grams of the sodium hypochloride solution.

The proportions of the corrosion inhibitors disclosed herein may vary from about 0.1% to about 2% by weight based on the oil. In the less corrosive and more stable oils 0.25% is sufiicient, while in more corrosive and less stable oils 1% or more may be necessary. The lighter grades of lubricating oils require somewhat more compounding. In an oil such as a solvent refined S. A. E. 30 lubricant from Kettleman Fields, California crude, 0.25% of the corrosion inhibitor has been found sufllcient even in the presence of other stabilizers such as metal phenates.

In general, it has been found that the corrosion inhibitors of this invention are outstanding and not the mere equivalent ,of the various other sulfides. For example, the same corrosion inhibiting action in over-refined or high viscosity index lubricating oils is not obtainable with ordinary thioethers or disulfides of the type formulae:

respectively. The multi-bridged sulfur structures give a corrosion inhibiting action, particularly in over-refined oils or oils having a viscosity index greater than 75, under conditions where various other thioethers and disulfides of the conventional structure are not fully satisfactory. For example, an S. A. E. 10 lubricating oil from a 'certain Colombian crude is a particularly diflicult QQQQQTFQQHMEH eia iili esaeaia tseom In hi etbem ynefore weighing, each strip was washed in petroleum ether and carefully wiped with a soft cotton cloth. The duration of the test was 72 hours. in weight in milligrams in the foregoing corrosion 6 test is termed the corrosion index of the oil. shown by In test 1 the temperature was 325 F. as indicated. Ten liters of air per hour were bubbled Test bearing Dost 1. 320 Mg, zm m high 3 F, ltrlpcoc- 'a 35% Diesel rosiontect- 't 10 rag. wt. ion mg.wt.|ocs. MM f connsctmg nnegalned m rod Cn-Pb 12 hours b 061m. 2mm.

x... lan8.A. E."0.,. tel 11 to .25 m gfi asiapnm-fitgz zfmag zoo 55 1am Colombian 8. A. E. lo+0.fi%nillurlzdd metol phenom-H.259; metal orpno;pbonphste+l=t%cutyl.ctb lsuldde 12.2 88.3 40 I 150 Coiombian8.A.Ei"l0+0;5% H" metflphcnate-l-O.26%metal I prgauophosphatH-l? paraflinparaflln wax thiomer having substantially the same sulfur content. This is illustratedby thefollowing data:

coarse Cu-Pb, 72 hours From these data it is evident that the paraflin wax thiomer is from four to eight times as effective as cetyl ethyl sulfide, and over three times as eifective as a conventional diallwl disulflde structure with about the same sulfur content in the *inhibiting agent. The limit established by the Caterpillar Tractor Company in the high speed Diesel engine corrosion test is 50 mg. in 246 hours for oils of exceptional quality." The above data show that paraflin wax thiomers are capable of producing an oil meeting the test for exceptional quality, whereas the other sulfides, although highly effective as corrosion inhibiting agents, do not yield an oil of exceptional quality with Colombian base stocks. As stated above, it should be borne in mind that this Colombian base stock is very difiicult to handle from the corrosion standpoint, and this particular type of oil was selected for the above tests in order to emphasize the exceptional properties of the corrosion inhibiting agents herein disclosed.

The strip corrosion data above given were obtained in corrosion tests carried out in the following manner: Glass tubes two inches in diameter and twenty inches long were immersed in an oil bath, the temperature of which was automatically controlled to within -i-.1 F. of the test temperature indicated. Approximately 300 cc. of oil under test was placed in each tube and air was bubbled through it. Strips of the different types of the bearing metals were placed in the oil. The weight loss of each strip was recorded. Be-

engine by operation under the following conditions:

R. P. M 1400 Brake horsepower 32 Jacket temperature .31"... 200 Oil sump temperature .......F 210 Air to radiator ..-...F... 125 Oil chang hnure 6o through the test oil and a copper catalyst was utilized.

In test 2 the temperature was 300 F. as indicated. 30 liters of air per hour were. bubbled through the test oil and both a copper strip and 10 grams of steel wool were placed in the oil as catalysts. The bearing metal subjected to corrosion in test 2 was a strip of coarse-grained copper-lead bearing. This second type test is the one designated previously for characterizing over-reflnedoils.

Test 3 is carried out in a high speed Diesel possible to obtain oil dispersions of the solid products but a liquid viscous readily oil-soluble thiomer is preferred, as previously noted. I

The present invention also provides multifunctional additives for lubricants. Such multifunctional compounds are capable of simultaneously inhibiting piston ring sticking or varnish formation and reducing corrosion. Examples of such multi-functional additives are aryl metal oxides containing a multi-bridged thio grouping and metal carboxylates containing such a grouping. In general, the presence of multi-bridged sulfur grouping in metal salts of oil-soluble organic acids imparts multi-functional characteristics thereto.

The loss where X is preferably phosphorus, but may be arsenic or antimony.

lg F scism i ll Calcium salt of 1,4-dithiane-2,5-di-(octadecyl lphenylf carboxyiic') acid Y Calcium salt of 1,4-dithiane-2,5-di-(eicosyl phenyl carboxylic) acid b '5 Calcium salt of 1,4-dithiane-2,5-di-(paramn wax phenyl carboxylicl acid Calcium salt of 1,4-dithiane-2,5-di-(he1wl hydromhen'yi carboxylic) acid Calcium salt of 1,4-dithiane-2,5-di.-(octyl hydroxyphenyi carboxylic) acid- Calcium salt of 1,4-dithiane-2,5-di-(decyl hydroxylphenyl carboxylic) acid Calcium salt oi. lA-dithiane-Zj-diJdodecyl hydrcxyphenyl carboxylic) acid alcium salt of 1,4-dithiane-2,5-di-(cetyl hydroxyphenyl carboxylic) acid Calcium salt of 1,4-dithiane-2,5-di-(octadecyl hydroxypheriyl carbomlic) acid Calcium salt of 1,4-dithiane-2.5-di-(eicosyl hydroxyphenyl carboxylic) acid Calcium salt of 1,4 dithiane-2,5-di- (para'flln wax hydroxyphenyl carboxylic) acid Other metals may be substituted for calcium, e. g. barium, strontium, magnesium, aluminum, zinc, tin and chromium.

METAL SALTS OF ORGANO-INORGANIC ACIDS CONTAINING MUL'I'I-BRIDGED THIO GROUPS 3o Exemplary are metal salts of acids-of-the following type formulae:

n o Em l o- -1,4-dithiane-3,5-dicar- -di-,paraflln wax-lA-dithiane-(ifi- 15 c dicarboxylic acid Zinc salt of 2,6-di-hexadecenyl-l,4-dithiane-3,5-

Aluminum salt oi! 2,6-di-hexadecenyl-L4-dithiane-3,5-dicarboxylic acid Zinc salt of 2,6-di-octyl-1,4-dithiane-3,5-dicarboxylic acid Zinc salt 01' 2,6-di-decyl boxylic acid Zinc salt of 2,6-di-dodecyl1,4-dithiane-3,5-dicarboxylic acid Zinc salt of 2,6-di-cetyl-1,4 dithiane-3,5-dicarboxylic acid Zinc salt of 2,6-di-octadecyl-1,4dithiane-3,5-dicarboiwlic acid Zinc salt of 2,6-di-eicosyl-i,4-dithiane-3,5-dicarboxylic acid Zinc salt of 2,6

dicarboxylic acid Other metals may be substituted for aluminum 20 or zinc, e. g. calcium, barium, strontium, magnesium, tin and chromium. METAL SALTS 0 A'RYL CARBOXYLIC ACIDS CONTAINING MULTI-BRIDGED THIOAL- Y GROUPS Examumw TYPE Fonuunar: I

where-R is a radical of hydrocarbon structure.

' Examuzs Calcium salt of 1,4-dithiane-2,5-di-(hexyl phenyl where P is phosphorus.

carboxylic) acid Calcium salt of 1,4-dithiane'-2,5-di-(octyl phenyl carboxylic) acid Calcium salt of 1,4-dithiane-2,5-di-(decyl phenyl carboxylic) acid Calcium salt of 1,4-dithiane-2,5-di-(dodecyl phenyl carboxylic) acid Calcium salt of 1,4-dithiane-2,5-di-(cetyl phenyl carboxylic) acid lll I where B is boron.

EXAMPLES Calcium salt of 1,4 -dithiane-2,5-di-(octylphosphoric) acid Calcium salt of 1,4-dithiane-2,5 -di-(decyl phos-- phoric) acid Calcium salt of 1,4-dithiane-2,5-di-(dodecyl phosphoric) acid 1 Calcium salt of l.4-d ithiane-2,5-di-(tetradecyl phosphoric) acid Calcium salt of 1,4-ditl'iiane-2,5- ii-(cetyl phosphoric) acid Calcium salt of 1,4 -dithiane-2,5-di-(octadecyl' phosphoric) acid Calcium salt of 1,4-dithiane-2,5-di-(eicosyl phos- .-phoric) acid at elevated temperatures.

fide group is desired, then a mercapto group may be introduced into the alkyl portion of the mole- -have been partially esterified, salts of alkyl carboxylic acids containing a polar group near a carboxyl grow of the acid, and metal alcoholates.

Incorporation of the multi-bridged thioalkyl compounds heretofore disclosed in hydrocarbon oils having a viscosity index greater than 75 or Calcium salt of 1,4-dithiane-2,5-di-(paramn wax phosphoric) acid Calcium salt of 1,4-ditl'iiane-2,5-di-(octyl phosphorous). acid v Calcium salt of 1,4-dithiane.-2,5-di-(decyl phosphorous) acid Calcium salt ofphosphorous) acid Calcium salt of 1,4-dithiane-2,5-d i-(tetradecyl phosphorous) acid Calcium salt of 1,4-dithiane-2,5 di-(cetyl phosphorous) acid 1,4-dithiane-2,5-di-(dodecyl Calcium salt of igl-dithiane-2,5-di-(octadecyl phosphorous) acid Calcium salt of 1,4-dithiane-2,5-di-(eicosyl phosphorous) acid Calcium salt of 1,4-dithiane-2,5-di-(paramn wax phosphorous) acid Calcium salt of 1,l-dithiane-2,5-di-(octyl boric) I acid Calcium saltof 1,4-dithiane-2,5 -di-(decyl boric) acid Calcium salt of l,4-d ithiane-2,5-di-(dodecyl boric) acid Calcium salt of l,4-dithiane-2,5-di-(tetradecyl boric) 'acid Calcium salt of 1,4-dithiane-2,5-di-(cetyl boric) acid Calciumsalt of 1,4-dithiane- -2,5-di-(octadecyl boric) acid Calcium salt of l,4-dithi ane-2,5-di- (eicosyl boric) acid alcium salt of 1,4-dithiane-2,5-di-(paraflln wax boric) acid r Other metalsmay be substituted for calcium, e. g. barium, strontium, magnesium, aluminum, zinc,-tin and chromium.

The foregoing multi-functional addition agents may be prepared by various methods. For example. the same type of reactions disclosed at page 3 of this specification may be applied to these compounds by chlorinating the alkyl portion of the molecule and reacting the chlorinated product with an alkali metalsulfide containing stabilizers.

over-refined oils enhances the responsiveness of these oils to the immediately foregoing types of Thus the multi-bridged thioalkyl compounds act as sensitizers in high viscosity index or over-refined hydrocarbon oils for stabilizing agents of the anti-piston ring sticking type. The corrosion inhibitors herein disclosed are accordingl mum-functional and are therefore'both a sensitizer andlan inhibitor of corrosion.

The corrosion inhibitors hereinbefore disclosed cooperate with aryl metal oxides to give a superior oil. Examples of aryl metal oxides are polyvalent metal salts of phenols of the type for- V mulain which u, v, w, 21: and u are selected from the group consisting of hydrogen or radicals of hydrocarbon structure. The phenol preferably contains at least one alkyl group having more than four carbon atoms. The term "radicals of hydrocarbon structure is .intended to include alkyl, aryl, "aralkyl, alkaryl or cyclic nonbenzenoid groups which may or may not contain inorganic substituents. Likewise, this term includes radiscals which contain hydroxyl groups, ether, thioether, keto, thioketo or carboxyl groups.

The aryl metal oxides also may be metal salts kaline earth metal salts of phenols containing, a

thio compounds. When a multi-bridged disuldecyl, dodecyl, tetradecyl, cetyl, octadecyl, eicosyl or wax substituent; aluminum salts of phenols containing a decyl, dodecyl, tetradecyl, cetyl, octadecyl, eicosyl or wax substituent; magnesium salts of phenols containing a decyl, dodecyl, tetradecyl, cetyl, octadecyl, eicosyl or wax substituent; and similar salts of alkyl substituted polyhydroxy phenols. Other metals, erg. tin, zinc. cadmium, chromium, iron, cobalt and nickel, may be substituted for the foregoing metals.

These compounds'may b prepared by methods disclosed in the art. The following data exemplify the eifectiveness of the corrosion inhibitors assent? disclosed in reducing the corrosivity of bricants containing m1 metal oxides:

Sulfurized metal phenates are particularly useful in combination with the multi-bridged sulfur corrosion inhibitors herein disclosed. The sulfurized metal phenates may be formed byreaction of the foregoing aryl metal oxides, par ticularly polyvalent metal salts of mononuclear phenols,.with a small amount of sulfur. About 1 6 to 1 gram atoms Of sulfurper mol of metal phenate may be utilized in carrying out'the sulfurization reaction. Preferably, the weight of sulfur is equivalent to about to l gram'atom per mol of the phenate. The reaction of the sulfur and metal phenate is desirably carried out in an organic solution. For example, the metal phenate may be dissolved in a small amount of a hydrocarbon oil to form a concentrated solution of 50% by weight or more of the phenate in the oil. The preferred proportion of sulfur is then added to this solution, the reacting ingredients stirred and h ated. at 300 to 320 F. for about one hour, or until substantially complete reaction is obtained as indicated by the fact that a copper strip will show only a reddish-purple coloring after five minutes submersion in the reaction mixture at 300 F.-

Examples of aryl metal oxides which may be.

where R and R1 are radicals of hydrocarbon structure and M, is a metal, preferably a polyme such as calcium. barium, strontium, esium, zinc. tin and chromium.

The efiectiveness of-the corrosion inhibitoraof this invention in combination with the above -i1- e substituted aryl metal oxides is shown by the following data:

825 E2, strip eorr. teetmg. wt. loaa Oil 24 hrs. 48 hrs. 72 hrs.

. Solvent refined oil base 8. A. E. 30 (VI 86)+0.75% metal phenate disulflde. l7. 2 2i. 3 32. l Solvent refined oil base S. A. E. 30 (VI- 86) +0.75% metal phenata disulflde+ 1% pamiiln wax thiomer l 5 3. 7 6. 4 Standard Dlol HD (VI=37) 29.3 89.4 112. 2 Standard Dlol HD (VI=37)+1% paraflln wax thlomer l2. 3 16. 1 18. l

An oil solution ofa metal phenate containing an aryl sulfide groumand of the type listed in the foregoing table may be obtained under the trade-name "Paranox 56, a product of Standard Oil Company of New Jersey. il of the Paranox 56 may be added to the oil to obtain 0.75% by weight based on the oil of the metal phenate containing an aryl sulfide substituent. The Standard'Diol HD referred to in the above table is an all sold under that -brand name by Standard Oil Company of New Jersey and is believed to contain a small amount of a compound of the type formula:

HOMO onion where R is a radical -01 hydrocarbon structure; a

M is a metal. e. g. calcium, barium, strontium,

magnesium, cadmium, zinc} aluminum, tin, chromium, iron, cobalt or nickel; and X is a substituent such as NH:, NR:, OH, --Cl, Bi', -'-I, -No., -o1vi --SH, --CN, -SCN, and the like.

The effectiveness of this combination is illustrated by the iollowing data:

325 F.. strip corr. testmg. wt. loss Oil 24 hrs. 48 72 hrs.

Kettleman (Calif.) S. A. E. 30 (VI=86)+ 0.5% calcium polyamyl naphthoyl benzoate 50.7 154. 9 179. Kcttlernan (Calif) S. A. E. 30 (VI==86)+ 0.5% calcium polyamyl na hthoyl benzoate.+l% parafliu wax th mer 11.9 12.3 12. 3 Sooony-VacuumRDB-ZOE) (VI =64) 28. 7 76. 7 107. l Socony'Vacunm HD8403 (VI=64)+1% paraflin wax thiomer 24. 5 48. 7 52. 3

The calcium pol'yamylinaphthoyl benzoate referred to in the above table is a compound of the type Iormula-- (CsHn) C. (coon).

cm). coon): ROOC (cm). coon in which n may be zero or a, whole number generally from 1 to 8 inclusive, :4: is a whole number from '1 to n, and in which there may or may Kettleman (calm) s. a. E. 30 (VI=86) Cyanate. --OCN Thiocyanate, -SCN and the like.

The effectiveness 01 this combination is illustrated by the following data:

24 hrs. is hrs. 12 hrs.

+0 6% calcium cetgl citrate 2. 5 3. 5 4. 3

Kettleman (CaliL) 0.5% calcium cetyl citrate+1% p raflln wax thiomer 0.8

Calcium, barium, strontium, magnesium, zinc,

cadmium, aluminum, tin, chromium, iron, cobalt and nickel salts of the polycarboxylic acids, preterably partially esterifled, may be utilized. Ex-' amples of acids from which such salts may be prepared by known methods are: oxalic acid, malonic acid, isosuccinic acid, glutaric acid, adipic acid, pim'elic acid, suberic acid, 'sebacic acid, iu-

maric acid, maleic acid, malic acid, tartronic acid, tartaric acid, citric acid, aminosuccinic acid and the like. It is preferred that each of the above acids be partially'esterifled andthat the metal salts be a salt of a partially esterified acid.

Examples oi salts of alkyl carboxylic acids containing ,a polar group near a carboxyl group of the acid are: the calcium, barium, strontium, magnesium, zinc, tin, aluminum, chromium, iron, cobalt and nickel salts of alpha, beta or gamma hydroxy lauric, myristic, palmitic, stearic and arachidic acids; the calcium, barium, strontium,

" magnesium, zinc, tin, aluminum, chromium, iron.

not be alkyl, aryl, aralkyl or carbocyclic substi- Metallo-carboxyl, COOM Hydroxyl, -0H

Amino, NH2

Metallo-oxy,--OM

Thioketo, =S

Mercapto, -SH

Cyano, --CN cobalt and nickel salts of alpha, beta or gamma thio, mercapto, mercaptide or thiono substituted lauric, myristic, palmitic, stearicand arachidic acids; and thecalcium, barium, strontium, magnesium, zinc, tin, aluminum, chromium. iron, cobait and nickel ,salts of alpha, beta or gamma amino substituted lauric, myristic', palmitic. stearic and arachidic acids. 'Iheeflectiveness of these salts in lubricating oils may be enhanced by use in combination with the multi-bridged thioalkyl compounds herein'disclosed.

Examples of metal alcoholates which may be added to hydrocarbon oils together with the multi-bridged thioalkyl inhibitors comprise the alkali, alkaline earth, aluminum andheavy metal alcoholates, e. g. sodium, potassium, calcium, barium, strontium, magnesium, zinc, cadmium, tin, aluminum, chromium, iron. cobalt and nickel alcoholates. Examples of alcohols utilized to form the metal alcoholates are the higher alcohols, such as amyl, hexyl, heptyl, octyl, nonyl, dec'yl, dodecyl, tetradecyl, hexadecyl, octadecyl, ceryl,

- myricyl and unsaturated alcohols, such as are derived from lanolin.

For purposes of clarity and emphasis it is again pointed out that each of the multi-bridged thioalkyl compounds, and particularly the paraflin wax thiomers hereinbefore disclosed, may be utilized either as a corrosion inhibitor or as a sensitizer for hydrocarbon oils to be stabilized with any or the aryl metal oxides, salts of aryl carboxylic acids, salts of polycarboxylic acids, salts 01' alkyl carboxylic acids containing a polar group, and the metal alcoholates above disclosed. In some instances, as for example in over-refined or high viscosity index oils having a viscosity index greater than '75, the principal function voi the thiomers may be that of a sensitizer rather than a corrosion inhibitor. In other instances, as when the hydrocarbon oil being stabilized is only moderately refined or has a viscosity index less than 75 and the service to be encountered by the compounded oil is severe or with corrosionsensitive bearings, the principal function of the thiomers may be that of a corrosion inhibitor. In still other situations the thiomers may serve as multl-functional agents to both inhibit corrosion and sensitize the base oil to stabilization with the salt-type inhibitor.

The proportion of the salt-like inhibitors, that is. of the aryl metal oxides, salts of aryl carboxylic acids, salts of polycarboxylic acids, salts of alkyl carboxylic acids containing a polar group, and the metal alcoholates above disclosed, may vary from about 0.1% to 2% by weight in the finished oil. From approximately .5% to 1.5% is usually preferred.

Another aspect of this invention comprises the provision of an activator for the multi-bridged thioalkyl compounds disclosed herein. These activators enhance the effectiveness of the thiomers herein disclosed in a manner which has not been explained and is not understood. The activators preferably comprise either an acid ester, that is, a partially esterifled acid of a strong acid-forming element such as phosphorus, or of a weak acid-forming element such as arsenic, antimony, or boron, or a salt of acids of these strong or weak acid elements containing an organic substituent, Acid esters or salts of partial esters of acids of silicon and of metacarbonic or orthocarbonic acids are also contemplated within the broader aspects of the. invention. Either the acid ester alone, or the salt alone, or mixtures of salts and acid esters of any of the foregoing may be used as an activator. These types of activators, when utilized in combination with the foregoing multi-bridged thioalkvl compounds, enhance the corrosion inhibiting or sensitizing action thereof. 7

This is true even though the activator may not, when added alone, be a sensitizing agent for the oil being stabilized.

Illustrative activators which may be added to hydrocarbon oils, such as mineral lubricating oil,

according to this invention comprise metal salts I ably formed from substituted oxyacids of pentavalent phosphorous'of the following type formula:

where B. may be alkyl, aryl, alkaryl, aralkyl or cyclic nonbenzenoid radicals. Substituted phosphoric acids containing at least twelve carbon atoms are preferred, but where the salts are sufllciently soluble in oil, acids containing fewer carbon atoms may be utilized. Examples of preferred type acids are alkyl or alkaryl substituted phos-- phoric acids having at least twelve carbon atoms in the molecule. It is to be understood that the broader aspects of the invention include salts of other types of acids of phosphorus containln! more thantwelve carbon atoms. Additional examples of such substituted oxyacids of phosphorous are as follows:

P mphonic acid Monaester of phosphonic acid P-OH Pholphiulc acid where R and R1 may be alkyl, aryl, alkaryl, aralkyl or cyclic nonbenzenoid groups which, in turn, may be pure hydrocarbon constituents or oxygenated hydrocarbons such as alcohols, ketones, esters and ethers, or hydrocarbons containing substituents such as halogens (chlorine, bromine, iodine), amino, or nitro groups. Likewise R. and R1 may be an oil-solubl heterocyclic constituent, for example, a radical containing a nitrogen ring. a

In general, salts of substituted derivatives of acids of phosphorus, such as phosphorous acid, HaPOa; hypophosphoric acid, HaPOa; orthophosphoric acid, H2904: pyrophosphoric acid, 114F201, and the sulfur analogues of these acids fall within the broadest aspects of the. invention. By acids of phosphorus containing an organic substituen or by "substituted acids of phosphorus wherever used herein it is intended to designate acids of phosphorus containing an organic group of the types previously listed. The organic gro p may be either directly attached to the phosphorus atom of the compound or attached thereto through an intervening atom, such as oxygen or sulfur. The term oiwacids of phosphorus is used to designate throughout the specification and claims acids of phosphorus in which only an oxygen atom may intervene between the hydrogen and phosphorus atoms of the parent acid.

Additional examples of activators comprising derivatives of weak acid-forming elements are metal salts or acid esters derived from acids selected from the following groups:

TYPE 1,-Aoms or Boson Comammc m Onamrc Suasrrrornr Organic boronlo um;

a-on 3 Organic borinic mu R-O-B Monoosters of othoboric acid B.Dioraano acids of silicon suoa I Si\ C. Triorgano acids of silicon D.Pari:ial esters of monO-orthosilicic acid R-Bi-OH In all of the foregoing type formulae R, R and R" are radicals of hydrocarbon structure. It is understood that by the term hydrocarbon structure it is intended to include hydrocarbon groups containing polar radicals such as OH, SH, Cl, NH: and COOH. Likewise, this term includes radicals containing ether, sulfide and ester groups.

It should be borne in mind that in the foregoing type formulae all of the acids listed may not exist as such and that it is the esters or saltlike derivatives thereof with which th present invention is concerned. Accordingly. existence of the free acid in a stable form is not a prerequisite to the preparation of the derivatives thereof contemplated herein. It should also be observed that various of the salt-like derivatives are relatively insoluble in organic solvents such as hydrocarbon oils. However, oil-solubility is not an absolute prerequisite for utility of the present invention in its broadest aspects, as will be explained in more detail hereinafter; nevertheless, oil-soluble compounds ar preferred. Some of the salt-like compounds and esters ar unstable at high temperatures. When the compounded oil is to encounter high temperature conditions during use compounds known or found to be more stable at elevated temperatures should be selected.

Activating agents contemplated within the broader aspects of the invention are in general salts, and preferably polyvalent metal salts, of the following acid reacting compounds: organic substituted derivatives of acids of boron, such as orthoborlc, HsBOa; mesoboric, 11413205; metaboric, 112E204; dihydrodiboric, HlBzOa; hexahydrotetraboric, H6B4o9 (once called pyroboric acid); dihydrotetraboric, H2B4O'1; hexahydrohexaboric, HeBsOiz; dihydrohexaboric, HzBsOio; hexahydrooctoboric, HeBaOis; dihydro-octoboric, HaBsOrs; dihydrodecaboric, HzBmOm; dihydrododecaboric, HzBrzOm; organic substituted derivatives of acids of arsenic, such as alkvl arsine hydroxides or oxides, alkyl arsine sulfides, dialkyl arsine hydroxides or oxides, dialkyl arsine sulfides, aryl arsine hydroxides or oxides, alkaryl arsine hydroxides or oxides, aryl or alkarylarsine sulfides and sesquisulfides, diaryl arsine hydroxides or oxides, dialkaryl arsine hydroxides or oxides, diaryl or dialkaryl arsine sulfides, alkyl arsonic acids, alkyl arsine disulfides, alkyl arsinic acids, aryl arsonic acids, aryl di-arsonic acids, halogenated aryl arsonic acids, nitroaryl arsonic acids,

amino aryl arsonic acids, hvdroxy aryl arsonic acids, carboxy aryl arsonic acids, alkaryl arsonic acids, alkaryl diarsonic acids, halogenated alkaryl arsonic acids, aryl arsinic acids, alkaryl arslnic acids, aryl trithio-arsonic acids, alkaryl trithioarsonic acids, aryl arsine disulfides, and alkaryl arsine disulfides; organic substituted carbonic acids, such as monoesters of metacarbonic acids, mono-, diand tri-esters of orthocarbonic acids, including the thio derivatives of both the meta and ortho acids; organic substituted acids of silicon, such as mono-, dland tri-organo acids of silicon, and partial esters of mono-orthosllicic acid organic substituted acids of germanium,such as trisubstituted germanols, germanonic acids,

and zermanic acid anhydrides; organic substituted acids of tin, such as organo stannonic acids and organo thio-stannic acids; organic substituted acids of antimony, such as organo stibinous acids, organo stibonic acids and organo stiblnic acids; and analogous weak acids of bismuth, chromium, molybdenum, and manganese in those instances where organo salt-forming acids are obobtainable.

The proportion of activating agents herein disclosed which may be added according to the principles of the present invention may vary depending upon the uses involved and the properties desired. As little as 0.05% by weight of various of the compounds gives measurable improvements. From approximately 0.1% to 2% of the compounds may be added to liquid lubricants. In general, from approximately 0.25% to 0.75% has been found preferable, particularly when used in conjunction with from approximately 0.25% to 1% of an aryl metal oxide and 0.5% to 1.5% of the paraflin wax thiomers.

A preferred embodiment of this invention provides a mineral oil composition containing three types of components, namely:

( 1) A metal salt of an organic acid in an amount sufllcient to inhibit deterioration of the oil. This type of stabilizing agent has been previously disclosed herein in detail and examples given of aryl metal oxides, salts of aryl carboxylic acids, salts of polycarboxylic acids which preferably have been partially esterified, salts of alkyl carboxylic acids containing a polar group near a carboxyl group of the acid, and metal alcoholates. These salts, as hereinbefore disclosed, may be used in this preferred embodiment;

(2) A corrosion inhibitor and/or a sensitizer in an amount sufilcient substantially to reduce corrosion and/or enhance the responsiveness of the hydrocarbon oil to the stabilizing action of the metal salt stabilizer. When the base oil being stabilized is of high viscosity index or over-refined, this second ingredient usually functions primarily as a sensitizer. When the base oil is of low viscosity index or low refinement, the ingredient may serve primarily as a corrosion inhibitor. In moderately refined or moderate viscosity index base oils, this type of ingredient serves both as a sensitizer and a corrosion inhibitor. The corrosion inhibitor and/or sensitizer is a long carbon chain multibridged thioalkyl compound of the type previously disclosed herein. The many examples given in this specification may be utilized in the present preferred embodiment of the invention but, as previously indicated, the paraffin wax thiomers are outstanding.

phosphorus, arsenic. antimony or boron, or a salt or acids of these elements containing an organic substituent, as disclosed hereinbefore. The salts of other analogous organo-inorganic acids disclosed herein are not precluded as activators and fall within the broader scope of the invention.

The following data on oils compounded with the above three types of ingredients are illustrative:

.The compounded hydrocarbon oils herein disclosed may have one or more advantages depending upon the particular compounding agent or combination of compounding agents selected, the proportions utilized, and the environment which the lubricating oil is to encounter. It should be observed, for example, that even though a compounded oil may be somewhat corrosive to one particular type of bearing alloy, otherbearings may be little if at all aflected by such corrosive action. Hence, compounding agents or combinations thereof which may not be particularly desirable for lubrication of a special type of bearing. where corrosion becomes a factor of importance,

TABLE I 325 F. strip corrosion test on S. A. E. oil from Kettleman crude (California) +0.5% sullurized calcium cetul phenate+0.25% calcium cetz/l phosphate+0.25% thiomer Multi-bridged tblomer compoundifig agency Cu-Ph wt. loss mmg. P Percent P m Yum g i erererce 0. use u e g. g?" cent cent 2: by wt. Preparation byl s 01 wax in on 24 hrs 48 hrs 72 hrs 0 11.0 30.5 44.0 7.6 1.28 1753 680 12.2 11.5 26 0.25 Reaction of chlorinated parai- 0.7 1.7 4.4 4.4 0.83 1

3 26 0 25 111:: wax with sodium sulfide. +0 3 o 0 4 L 0 3031 936 13.3 10. 0 1. ".6 .46 2 1012 504 7.5 3.7 15.4 0.25 Reaction of chlorinated lubri- 3.6 11.0 14.2 7.8 1.94 16 cggnig oil with sodium s e. 913 860 10. 9 7 16 0. 25 Oxidation paraflln wax poly- 0. 6 2. 2 2.6 1 3. 2 1. 61

mercaptan to dis dc. 590 873 6.8 2.2 16 0.26 Reaction wax polymereaptide 6.3 16.7 19.1 7 1 1. 15 10 with chlorinated wax.

Tas a II 300 F. strip corrosion test (coarse grained bearings) on S. A. E. 10 oil from Colombian crude-141.5% suljarized calcium cetyl phenate+0.25% calcium cetyl phosphate+1% thiomer Multi-bridged thlomer compounding agency Ou-Pb wt. loss mmg. Percent 1 2223 Neut. Naphtha M 1 Per- Per- 01m Percent at F No. insoluble logi 2%? w? cent Gem Orig. by Preparation by- 9 C1 wax I 24 hrs. 48 hrs. 72 111's.

2c 1 Re t n ichl intd i 3: 3'; 38'; it? 2 1 0 12.2 11.5 acre 0 or es para- 68 R :1 vsr m ar t- 7 .7 8 15 550 11.1 12.6 26 eac 011 O or a 13 par 3. 34. 2.0 1.32 27 61 fin wax with sodium sulfide 7 s 1 R t 2 53's.. 1; d a! 2 0 1 2 c 9 30 s 1 12.6 1. 1 eac 10D. 0 o a e par 0. 1 l. l. 1 m4 525 1 R t c%1 l l d +3 1 +3 2 3 7 s 18.0 1.0 16 eac ion 0 or a a para l. 5 0. 4 17 2886 1500 fin wax with sodium sulfide extra suliur). 1012 504 7.5 3.7 15.4 1 Reaction of chlorinated lubri- 3.7 22.1 65.9 2.1 2 19 25 gating oil with sodium sul- 8. 6.8 2.2 16 2 Reaction wax polymerca tide 2.0 15.6 29.6 2.0 1.43 24 873 1 owiithficblorinatgi wax. p I 0 2 8 1364 14.9 3.0 xi a n para 11 wax po y 12. 5.6 4 .2 0 14330 mercaptan to disulfide.

The strip corrosion tests in Tables I and 11 were carried out in the same manner as described 60 previously for 325 F. and. '300 F. corrosion tests, respectively.

In the compounded oils containing the combination of three additives as above described, the proportions may be as previously indicated, name- 1y, from about 0.1% to 2% by weight, and preferably from apprommately 0.5% to 1.5% by weight based on the oil, of the-salts of organic acids; from about 0.1% to about 2% by weight based on the oil of a corrosion inhibitor and/or sensitizer, and preferably from about 0.25% to 1.5% thereof; and from as little as 0.05% to 2% by weight based on the oil of the activator,

from approximately 0.25% to 0.75% being pref- 7B erable.

may nevertheless be highly useful and extremely advantageous in conjunction with the operation of internal combustion engines having corrosiveresistant bearing metals. Likewise, combinations of compounding agents which are not sumciently powerful to stabilize a particular on stock under the most extreme conditions may, nonetheless, be highly advantageous in such oils where the environment to be encountered is not so severe. The present invention in its broader aspects is therefore not limited to the particular compounding agent or combination oi ingredients giving the greatest stability or passing all of the very severe tests which have been devised. The invention embraces various of the less advantageous additives or combinations thereof which may find utility in particular applications where all posmoderately refined or less paraflinic lubricating oils or even low viscosity index lubricants.

The compounded hydrocarbon oils of this invention may be utilized as turbine oils, cable oils, electric switch oils, transformer oils and the like, as well as in crankcase lubricants for internal combustion engines and especially Diesel engines. The compounding agents of this invention may also be added to hydrocarbon oils containing additional ingredients, such as pour point depressants, oiliness agents, extreme pressure addition agents, blooming agents, compounds for enhancing the viscosity index of the hydrocarbon oil, thickening agents and/or metal soaps in grease- !orming proportions or in amounts insufflcient to form grease, as in the case of mineral castor machine oils or other compounded liquid lubricants.

In the foregoing disclosure an upper limit of approximately 2% by weight based on the oil of each of the compounding agents has been indicated as suflicient for a finished oil. The present invention also embraces solutions containing more than 2% of the novel combination of compounding agents. Concentrates containing high percentages of the additives of this invention comprise a convenient method of handling the compounding agents, and the concentrated solutions may be sold and used as addition agents for lubricants in general. Thus mineral oil solutions containing as much as 50% or more by weight of the compounding agents may be prepared. Such concentrated solutions are adapted for dilution with hydrocarbon lubricating oil to yield a finished product containing, for example, from approximately 0.5% to 1.5% by weight of a metal phenate; from approximately 0.25% to 1.5% by weight of a parafiin wax thiomer; and from approximately 0.25% to 0.75% by weight based on the oil of a metal salt or an acid of phosphorus containing an organic substituent. Concentrated solutions of the additives in organic solvents capable of dilution with mineral lubricating oil to form a homogeneous mixture containing the above proportions of compounding agents comprise a part of this invention.

While the character of the invention has been described in detail and numerous examples of the compounds given, this has been done by way of illustration only and with the intention that no limitation should be imposed upon the invention thereby. It will be apparent to those skilled in the art that numerous modifications and variations of the illustrative examples may be eifected in the practice of the invention which is of the scope of the claims appended hereto.

We claim:

1. A viscous hydrocarbon oil containing from approximately 0.1% to 2% by weight based on the oil of a polyvalent metal salt of an organic acid, from approximately 0.1% to 2% by weight based on the oil of a multi-bridged'thioalkyl compound containing the chomical groupi i -t i l I said compound having at least one long carbon chain, and from approximately 0.05% to 2% by weight based on the oil of a metal salt of an inorganic acid containing an organic substituent.

2. A viscous hydrocarbon oil containing a corrosion inhibitor comprising a multi-bridged thioalkyl compound containing the chemical groupsaid compound having at least one long carbon chain and being present in the oil in amount sufficient to inhibit corrosiveness of the oil.

3. A lubricating oil having a corrosion index greater than about 40 containing a corrosion inhibitor comprising a multi-bridged thioalkyl compound containing the chemical groupsaid compound having at least one long carbon chain and being present in the oil in amount suflicient to inhibit corrosiveness of the oil.

4. A viscous hydrocarbon oil having a viscosity index greater than approximately '75 and a corrosion inhibitor comprising a multi-bridged thioalkyl compound containing the chemical groupsaid petroleum wax thiomer being present in the oil in amount sufllcient to inhibit corrosiveness of the oil.

6. A hydrocarbon oil containing an aryl metal oxide containing a multi-bridged thioalkyl substituent characterized by more than one sulfur bridge between alkyl carbon chains, at least one of said chains containing at least about 8 alkyl carbon atoms, there being a sufllcient amount of said multi-bridged thioalkyl substituent in the oil to inhibit corrosiveness of the oil.

7. A hydrocarbon oil containing a metal salt Mantra, carboxylic acid 'containingaJmultibridged-thioalkyl substituent. characterized by more than one sulfur-bridge between alkyl carbon chains, at least one ofsaid chains containing at least about 8 alkyl carbon atoms, there being a sufllcient amount of said multi-bridged thioalkyl substituent in the oil to inhibit corrosiveness of the. oil.

8. A hydrocarbon oil containing a metal salt of an organo-inorganic acid containing a multi--' bridged thioalkyl substituent characterized by more than one sulfur. bridge between a-lkyl carbon chains, at least one of said chains containing at least about 8 alkyl carbon atoms, there being a sufllcient amount of said multi-bridged. thioalkyl substituent in the oil to inhibit corrosiveness' of the oil. 7 V

9. A composition comprising a hydrocarbon lubricating oil subject to deterioration and to formation of adhesive deposits at elevated temperature, an aryl metal oxide in an amount sufficient substantially to inhibit said deterioration, and an inhibitor capable of reducing the catalysis of corrosion by said aryl metal oxide without destroying the stabilizing action thereof, said inhibitor comprising a multi-bridged thioalkyi compound containing at least one long carbon chain.

10. A composition comprising a hydrocarbon lubricating oil subject to deterioration and to formation of adhesive deposits at elevated temperature, a salt of an aryl carboxylic acid in an amount suflicient substantially to inhibit said deterioration, and an inhibitor capable of reducing the catalysis of corrosion by said salt of Y an aryl carboxylic acid without destroying the stabilizing action thereof, said inhibitor comprising a multi-bridged thioalkyl compound containing at least one long carbon chain.

11. A composition comprising a hydrocarbon lubricating oil subject to deterioration and to formation of adhesive deposits at elevated temperature, a metal alcoholate in an amount sufficient substantially to inhibit said deterioration, and an inhibitor capable of reducing the catalysis of corrosion by said metal alcoholate without destroying the stabilizing action thereof, said inhibitor comprising a multi-bridged thioalkyl compound containing at least one long carbon chain.

- a multi-bridged thioalkyl compound containing at least one long carbon chain, and an activator for enhancing the effectiveness of said corrosion inhibitor comprising a salt of an organo substituted acid of an element selected from the group consisting of phosphorus, arsenic, antimony and boron.

13. A composition comprising a hydrocarbon lubricating oil subject to deterioration and to formation of adhesive deposits at elevated temperature, a metal salt of an organic acid in an amount suificient substantially to inhibit formation of said adhesive deposits, 2. multi-bridged thioalkyl sensitizer for the hydrocarbon, oil capable of enhancing its responsiveness to the stabilizing action of said metal salt, and an activator capable of enhancing the effectiveness of said thioalkyl sensitizer. I

14. A composition comprising a hydrocarbon lubricating oil subject to deterioration and to formationof adhesive deposits at elevated temperature, a metal salt of an organic acid in an amount sufilcient substantially to inhibit formation of said adhesive deposits, a multi-bridged thioalkyl sensitizer for the hydrocarbon oil capable of enhancing its responsiveness to the stabilizing action of said metal salt, and an activator comprising a salt of-an acid of phosphorus containing an organic substituent, said phos- .solvent of a polyvalent metal salt of an organic acid, a multi-bridged thioalkyl compound, and a polyvalent metalfsaltof a substituted acid of phosphorus containing an organic substituent, said concentrated solution containing more than 2% by weight based on the oil of each of said three ingredients, said solution being capable of dilution with mineral lubricating oil to form a homogeneous mixture containing from approximately 0.1% to 2% by weight based on the oil of the polyvalent metal salt of an organic acid, from approximately 0.1% to approximately 2% by weight based on the oil of the multi-bridged thioalkyl c mpound, and from approximately 0.05% to 2 o by weight based on the oil of the polyvalent metal salt of a substituted acid of phosphorus containing an organic substituent.

16. A composition comprising a compounded hydrocarbon oil subject to deterioration and to formation of adhesive deposits at elevated temperature, said compounded oil containing a metal salt of an organic acid in an amount suflicient substantially to inhibit said formation of ad hesive deposits, and a corrosion inhibitor capable of reducing corrosivity of said compounded oil without destroying the inhibiting action of said metal salt, said corrosion inhibitor being a multi-bridged thioalkyl compound characterized by more than one sulfur bridge between carbon chains, atleast one of said chains containing at least about 8 alkyl carbon atoms.

17. A composition comprising a compounded hydrocarbon oil subject to deterioration and to formation of adhesive deposits at elevated temperature, said compounded oil containing an aryl metal oxide in an amount suflicient substantially to inhibit said formation of adhesive deposits, and a corrosion inhibitor capable of reducing corrosivity of said compounded oil without destroying the inhibiting action of said aryl metal oxide, said corrosion inhibitor being a multibridged thioalkyl compound characterized by more than one sulfur bridge between carbon chains, at least one of said chains containing at least about 8 alkyl carbon atoms.

18. A composition comprising a hydrocarbon oil, a corrosion inhibitor capable of reducing the corrositivity of said oil, said inhibitor being a multi-bridged thioalkyl compound characterized by more than one sulfur bridge between carbon 

